Focusing arc lamp



(No Model.) 4 Sheets-Sheet 1.

J. J. WOOD.

FOOUSING ARC LAMP. No. 407,915. Patented July 30, 1889.

QM g; 21 m 735 L515 Rif W Nv PETERS; Pmwul m myrm, wnhlngmn. D. C.

4 Sheets-Sheet 2.

(No Model.)

J. J WOOD. FOGUS ING ARC LAMP.

No. 407,915. Patented July 30, 1889.

WG'SWQQM r6,

4 SheetsSheet 3.

(No Model.)

J. J. WOOD. POGUSING ARC LAMP.

No. 407,915. Patented July 30, 1889.

W/ 70 58 SE8 X? %e% N. PETERS. Pnom-Limn m her. wmmn len. I10.

(No Model.)

J. J. WOOD.- FOUUSING ARC LAMP.

Patented July 30, 188.9.

4 Sheet's-Sheet 4 N PETERS, Phmwunm m hur, waihinglommc.

NYVE/YTOP Wihmm rq,

' UNITED STATES PATENT OFFICE.

JAMES J. \VOOD, OF BROOKLYN, NElV YORK.

FOCUSING ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 407,915, dated July 30, 1889.

Application filed October 1, 1883- $erial No. 286,920. Glo model.)

T 0 all whom it 77T/CLZ/ concern.-

Be it known that 1, JAMES J. 00D, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Focusing Electric Lamps, of which the following is a specification.

This invention relates to electric-arc lamps wherein both the positive and negative carbons are connected to and moved by the feeding mechanism, the movements imparted to them being so speeded relatively as to maintain the arcinan invariable position during the consumption of the carbons. Lamps of this character are known as focusing lamps, their principal use being in connection with concave mirrors or convex lenses, or both, by means of which the rays of light from the lamp are concentrated and projected in approximately parallel direction. Lamps of this character are used as head-lights, signal-lights, search-lights, time.

In focusing electric lamps prior to my present invention. the construction and arrangement of the parts have usually been such that the carbon pencils were located above the mechanism case or head, the axis of the carbons being usually within the circumference of the case. An example of such a focusing-lamp is found in my patent, No. 279,512, dated June 12, 1883. Such prior to cusing-lamps have been found subject to the disadvantage of occupying an inconvenient amount of vertical space from the are or focus downward to the base of the lamp, so that when applied in a reflector-casing the reflector was necessarily elevated considerably above the bottom of the casing, or the base of the lamp had to project through the bottom of the casing or into a downward extension thereof constructed to receive it. As applied to those projector-casings which are hung in trunnions in order that the beam of light projected may be inclined upwardly or downwardly, such lamps have also been subject to the serious disadvantage of concentrating the weight too greatly beneath the focal axis, (which axis is preferably also the pivotal axis of the trunnions,) thereby necessitating that the upper part of the easing' should be heavily counterbalanced in order to approximately counterbalance the easing and bring its center of gravity into close approximation with its axis of suspension, so that it can be easily turned to any inclination by the operator. Focusing-lamps have also been proposed in which the carbon-supports and mechanism have been arranged to one side of the focal axis of the reflector; but such lamps are subject to other defects quite as serious as those of the more usual lamps already described.

My invention aims, chiefly, to overcome the disadvantages of prior constructions, and provide a focusing-lamp which shall be as compact as possible, the dimensions of which shall be distributed as nearly as possible above and below the focal axis, and the weight of which shall be so distributed that it shall act to counterbalance the weight of the reflector in a pivoted projector-casing and avoid the necessity of idle counterbalancing-weights.

My invention also provides several improvements in the construction and method of operation of focusing-lamps and in the regulator or feeding mechanism thereof.

Figure 1 of the accompanying drawings is a side elevation of my improved lamp inclosed in a pivoted projector-casing, which latter is shown in vertical mid-section. Fig. 2 is a front elevation of myimproved lamp removed from the projector-casing and shown on a larger scale, the carbons being omitted. Fig. 3 is a vertical transverse mid-section of the mechanis1ncase, standard, and base of the lamp, cut in the plane of the line 3 3 in Figs. 1 and 4. Fig. 4 is a plan of the base portion of the lamp in horizontal section on line 4 4 in Fig. Fig. 5 is a horizontal section, on a larger scale, through the mechanism-case in the plane of the line 5 5 in Figs. 1 and 8. Fig. (3 is a detail view of the negativccarbon holder.

Referring first to Fig. l, letA designate my improved focusing-lamp as a whole, and B the proj ector-casing inclosing it and having a concave or parabolic mirror B, fixed in it, as usual. The casing B is hung upon trunnion s, one of which is shown in dotted lines supported in bearings in the upright frame B", one arm of which is shown in full and dotted lin vs. The pivotal axis of the trunnions extends transversely through the casing and intersects the focus of the reflector and also the electric are.

For a full. illustration and. description of the projector here shown in part, refer-mice is made to my application for patent on i mprovementsin electric projectors, executed and filed simultaneously herewith, (application, Serial No. 286,019, filed ()ctolaal, 1888.) The pertions of the projector and projector casing shown involve no especial novelty, but are in general of well-known e .n1strnct'ion, and I do not deem it necessary to further describe them.

The electric lamp A is constructed with the usual head or nuzcln'tnism-case C, and the positive and negative carbon holders l) and l), which carry the positive and negative carbons or pencils E and l The carbons project; through. holes (L and ct in the reflector l3, as usual, and come together in the focus of the reflector.

The peculiar feature which clu'tracterizes my improved lamp is the arrangement: of the carbons in front ol. the meclianism-case U, as clearly shown in Fig. 1. This arrangement brings the case (J and the standard and base supporting it behind the locus of the reflector, instead of underneath the same orto one side thereot', as heretofore, so that their weight serves to connterbalance the weight of the reflector, since it comes ehiolly on the opposite side of the pivotal axis. This arrangement also enables the entire lamp to be brought within the cyli ndrical walls of theprojectoi casing, with the exception ol. the upper part ot the positive-carbon holder, which pro jects, as heretofore, above the upper circumference of the cylindrical portion of the casing and enters the usual hood 7;, ctmstructed to receive it. \Vith the best prior constructions of focusing lamps it has been necessaryto form the casing l; with a deep downward extension or pocket to receive the mechanism-case O and its supporting-stamlard and base, so that the weight: of these portions was brought beneath and at a considerable distance from the axis ot suspension, and not only failed to connterbalanee the weight of the reflector, but also, in order that the projector-casing might be balanced on its trunnion-axis, requiretil itself to be eonnterbalanced by the fitting of heavy balancing\veiglits into the upper portion of the casing, thereby making the latter excessively heavy and consequently rendering it dil'ficnlt to operate the projector and rendering the latter clumsy and unwieldy. My invention not only renders the projector much more compact, but also ent'i rely removes the necessity of the idle weights for counterbalancing the projector-Casing.

The mechanism-ease (l is mounted on a standard F, arranged centrallyand vertically beneath it, which standard terminates in a bottom plate 1-",which rests on a base t. This base is fastened. by screws or otherwise to a wooden board. (4, which is fixed to the bottom.

of the projector-casing. .lhrough the medium ol. the standz'ird and base-the etmstructimi oil which will. be presently explained 't'he ease C maybe raised and ltnvered btnlily or moved .l.'or\vard andback or laterally, in order that the arc may be brought by adjustment to the exact locns ol? the rellector.

The carbon-holders l) and II) are of novel construction. Vertical guides or slit'lewav's Ill ll: are fastened to the ineclianism-ease t, referal.)ly directly in :t'ront thereof, and the carbon-holdcrs .l) l) consist of ln'acket-arms (Z (1, provided. with any usual elann ts c (or gripping thecarbonsandterminatinginslides JJ, which move up and down against; the guides .11 ll, being guided and held in proper relative position by the latter. The carbonholders are provided, respeetively,with vert i cal racks c c, the former being attached at its upper end to the positive holder and the latter at its lower end to a negative holder, and extending past each other at,- a point between the holders,wh(.m theyare brought close together, at which point the racks are engaged by the respective pinionsfj" on a spindleor shalt Knvhich passes within the case and is actuated by the feeding or regulating meele naism, as will n'esently be described. The pinion f is ot' twice the diameter of the pinion f, and is engaged by its rack e on one side of its axis, while the other pinion is engaged by the rack e on. the opposite side of the axis, so that by the rotation of the shaft h the positi ve-carbon holder has a l'eedi ng movement'imparttal to it at twice the speed of the lliOVOIllQl'lt imparted to the negative holder, as usual in Focusing lamps, .in order to compensate for the greater rate of consumption oi. the positive carbon.

The 'iarticular constructirm of guides shown, and which is pret'ta'red, consists of two verticalparallel rods illv 11', arranged side by side close in trout ot the mechanism-case, fastened to the latter by a plate ll, which engages them near their middle, and tied together at top andv bottom by eross-lnaads 7t and 71 The carbon-holder slides J .l' consist of tubes fitting freely and sliding on the rods 11' ll, the two tubes on each slide being connected together by an intervtating. plate or web from which the bracket (/or springs. The racks c e are guidedand kept .in cngage ment with the pinions ff by means of a frame I), clamped on the rods .I[ ll above the plate ll, and consisting in the construction shown of. two collars or rack-guides tastened by set-screws on therespective rods, and a cros bar L screwed to them and extending across from one to the other, and the middle portion of which receives and terms a bearing for the end of the feeding-shaft .l\'.. ltollcrs a: .v are n-ovidcd in the raclegnides to take the thrust of the racks. By means of this ct'mstruction the carbon-holders are provided with a steady and unyielding mounting and their exact parallel movement is assured. The advantage is also gained of avoiding the passage of the rods through holes in the top and bottom plates or heads of the mechanism case, which holes are liable to admit moisture or dust. NVith my improved construction the.

only openin g in th e mechanism caseis the small hole through which the shaft K passes out. This construction of guides also possesses the advantage of greater compactness than could be attained if the carbon-holders were formed with sliding rods as usual.

The upper-carbon holder is provided with a oounterpoise-weight U, mounted on arms projecting rearwardly from the slide J, which serves to counterpoise the holder and avoids the tendency to tilt due to the weight of its arm (1, clamp c, and the long carbon being entirely to one side of the axis of the guides H. The lower-carbon holder might be similarly counterbalanced; but I do not consider it necessary.

I will now describe the feeding mechanism within the case 0, with reference especially to Figs. 3 and 5. In general this mechanism is of the same construction as that disclosed in several prior patents of mine, and is so well known as to require no special description here. The separating and feeding of the carbons are elfected by means of a main-circuit magnet or solenoid M and a shunt-mag net N, arranged face to face and acting oppositely upon an H-armature P, the cores of which enter the coils of the magnets M and N. This armature is pivoted to an open armature-lever or tilting frame Q, which is fulcrumed on screwst'ito the fixed standards of the case, and is retracted by a spring Q. A train frame or cage R is pivoted to the armature-lever Q at 7a, and at k is connected by a parallel-motion link Z to the top plate of the mechanism case. The cage R contains the several wheels and spindles of the feedingtrain, which train consists, essentially, of a leading pinion m and a detent or scape wheel at, with any desired number of intermediate wheels and spindles in order to multiply the motion to greater or less extent. When the train is elevated by the attraction of the magnetM, which is its normal condition in use, the scape-wheel n is moved by it into engagement wit-h a tooth or stop 92, which is mounted on or formed as part of a spring, and the movement of the train is thereby arrested; but when the train is lowered bodily by the tilting of the armature-lever Q, by means either of the retracting-spring Q or the shunt-magnet N, or both, the scape-wheel n is moved down far enough to clear the stop at, whereupon the train is released and the feeding operation takes place until again arrested by the lifting of the train by means of the attraction of the magnet M. This is the usual construction and operation of the feeding mechanism of my lamps.

In all lamps of this description heretofore made the leading or initial pinion on has been made to mesh directly with the rack of the positive-carbon holder, so that the latter is caused to participate in the bodily up and down movements of the train, by which means the striking of the arc is effected upon the tilting of the arm ature-lever and lifting of the train by the attraction of the main magnet M. This will be better understood on reference to some of my previous patentssuch, for example, as No. 261,289, dated July 18, 1882. According to my present construction, however, the leading pinion m meshes with a larger pinion or gear m on the feeding-shaft K, which shaft is mounted in fixed bearings, its outer end having its bearing in the cross bar L, as already described, and its inner end havingits bearing in a standard l, which descends from the top plate or head of the case C. The operation maybe best under stood by a comparison of Figs. 2 and 3, which are both views looking from the front. It will be seen that the pinion m engages the gear m on the same side of the axis of the feeding-shaft K that the positive-holder rack e engages the pinion f. Hence, when the magnet M acts to tilt the lever Q and bodily lift the train, the pinion m, which is held from rotating by the detent of the train, moves upward tangentially to the gear m, and acts on the latter as though it were a rack, thus partly rotating the gear m and shaft K, and consequently partly rotating the pinion f in the same direction and thereby propelling the rack e upward and lifting the positive-carbon holder and carbon. At the same time the smaller pinion f, having the same degree of rotating movement imparted by the shaft K, propels its rack e downward, and thereby lowers the negative-carbon holder and carbon a distance equal to half the lift of the posi-- tive holder. Thus the carbons are separated and the arc is formed.

The feeding is effected by the preponderance of weight and mechanical advantage of the positive holder and carbon over the negative holder and carbon, the weight of the former being transmitted through. the rack e to the pinion f, at twice the distance from the center of the shaft K that the weight of the negative holder is transmitted through the rack c to the pinion f, so that by this preponderance of weight and leverage of the positive holder the shaft K has imparted to it a tendency to rotate in the direction which will feed the carbons together. This tendency is normally resisted by the train so long as the attraction of the magnet M keeps the train lift-ed with its wheel a in engagement with the stop 12. but when, by the increase of the attraction of the shunt-magnet N, due to the lengthening of the are, the armature is lifted'and the train correspondingly lowered, the shaft K is revolved in the feeding direction, first by the bodily downward movement of the'pinionm, in which, being non-rotative, it acts like a rack upon the gear m, and subsequently, after the train is released by the freeing of the detent-wheel n, the shaft K is permitted further to rotate in the same diree t-ion and. to rotate the train with it, until the proper feeding has been effected, whereupon the feed is arrested by the lifting of the train, through the prepondcrating attraction of the magnet M, until the detent-wheel is again caught by the stop it.

In my said patent, No. 279,512, there is the same construction of tilting armature-lever and feeding-train having a bodily upward and downward movement; but the train has two leadingpinions, one of which engages directly with the rack of the positive-carbon holder and the other of which, on the same spindle of the train, engages with a gear on a shaft mounted. in stationary bearings, (and answering to the gear 777/ and shaft K of my present O()11St1?tl0tl()ll,) which shaft gears with the rack of the negativecarbon holder by means of a pinion, (answering to thepinionf of my present lamp.) My former construction necessitated, practically, that the rack of the positive. carbon should pass through the mechanism-case, and necessitated also the inter iosition. of an insulatin g-cou plin g in, the negati Vefeeding shat't. by utilizing the same shaft and stationary bearings as the feedingshaft for both carbon-holders I effect some simplification of the mechanism and enable the racks of the carbon-holders to be arranged exterior to the mechanism -case, which is practically of great advantage.

I will not herein describe the construction of automatic relightingcut-out which is shown, or the resistance-coil, or the manual switch for short-circuiting the lamp, since'these features are fully illustrated and described in my application, Serial No. 6,559, filed August 10, 1887.

I will. now describe the circuit-connections. The current enters by the positive bindingpost p and passes thence into the metallic frame of the lamp, flowing through the plate ll into the rods 11 ll, and thence through the positive holder D and positive carbon E to the negative carbon E, and through the clamp 0 thereof, the shank of which passes through the larger end of the bracket (7, and is insulated therefrom, shown in section in Fig. (5, and thence by the two flexible insulated wires (1 q to a boss q, which is insulated from and passes through the bot tom plate of the mechanism-case, and which within the case terminates inv abinding-post, to which is connected one terminal 'r of the coils of the main-circuit magnet M, through which the current flows, and passes out by the other terminal 1' thereof, which leads to the negative bindingpost p, by which. the current passes oti to the line.- The connections of the shunt-magnet coils and the resistance-coil for the relighting cutout are well understood and require no description. It will be observed that the main-circuit connections in my iiresentlamp ditter from those common in focusing-lamps, in that the clamp c of the negative-carbon holder is insulated from the bracket of the holder by a sheath of heat-resisting insulation-such as micaand is connected with the circuit in the mechanism-case through. the medium of the flexible wires (1 q, of which use two, by preference and as a protection. against; the accidental rupture of one of them, although one wire alone might be employed.

I have said that the staiulard F, which supports the lamp, is mounted adjustablyon the base-plate G, so that the lamp may be moved to different positions in a horizontal plane in order to adjust; the position of the axis of the carbons relatively to the reflector. This result is accomplished by the construction best shown in. Figs. and l. The standard F terminates at its bottom in. a plate or disk F, to which. the upper and tubular portion of the stem is connectedv through the medium of an arched frame F. The top of the base-plate G and the bottom of the plate F are made illat, so that the latter can restupon the former and may be moved thereon to diilfercnt positions. The plate F has a slot .5- formed through it and cxteni'ling in fore-and-aft di rect-ion or in a direction toward andv from the axis of the carbons, as shown in Fig. l, where the position of the carbons .is indicated at E. A set-screw S passes through the slot s and screws into the center of the base-plate (1, a washer being preferably interposed between the head of the screw and the top of the plate F, as shown. 13y loosening the screw S the plate F .is freed, and may be oscillated on the l; aseplate or moved. fore and aft in order to bring the carbons to the proper position in the reflector, after which, by screwing down the screw S, the plate F will be clamped firmly in place.

I provide for the adjustment of the carbons in vertical direction, in order to adjust the are up or down and. thereby bring it into the focus of the reflector by raising and lowering the case (1 bodily by means of a telesci'ipic construction of the stznulard F, as has been done heretofore. The case 0 is mounted on a tube t, the lower portion. of which is screwthreaded and slides telescopicallyinto a tube 15, which :is fixed to the arched frame F. A .nut it turns freely on the upper end of the tube t, and engages the screw-thread of the tube t, so that as the nut turned the tube! is propelled up or down. Hcretofore, in extensible standards of this character, the inner tube has been prevented from turning by means of a pin-and-slot connection with some stationary part, such as a pin. projecting inwardly from the tube 6 and entering a verti' cal slot in the tube '6. Such construction has been found objectionable because when the pin and slot become wor.n,as they soon do by use, a looseness or lost motion is develol'ied in lateral direction, which becomes greater the greater the distance from the axial center, so that at the carbons it amounts to a sutlicient play to materially disturb the fetal position of the carbons relatively to the reflector. In

my improved lamp this defect is entirely overcome by a different construction of vertical guide. In the bottom plate of the standard F, and as far from the center of the screw '6 as can be, is fixed a vertical pin or other equivalent guide y, the axis of which is parallel with that of the telescopic screw of the standard. The lower cross head h of the guide-rods H II has a backward extension which terminates in a forked guide n, embracing the pin 1 as best shown in Fig. 4. As the mechanism-ease C is raised or lowered by the turning of the nut a, the guide 0) travels up or down against the pin 3 and thereby serves to prevent the rotation of the meehanism-case around the screw-axis i. As the axis of the pin y is considerably removed from that of the screw 15, a given degree of lost motion would produce much less play at the carbons than with the pin-and-slot device heretofore used. The construction is such, furthermore, that wear is much less likely to occur than with a pin-and-slot guide, and the parts can be much more accurately constructed in the first instance. The head of the pin q serves as a stop to prevent screwing up the mechanism-case too high, and the lug into which the pin 1 is fastened serves as a downward stop to limit the descent of the meehan ism-case. The pin y and guide 1 also serve to some extent to steady the guide-rods II II and prevent any spring of the latter. The precise construction of the guides y '0 is not essential, as the pin and fork or notch might be reversed, or any other equivalent guiding construction located at the same point, or in substantially equivalent posit-ion, might be substituted.

IIeretofore telescopically screw-extensible standards have been operated to raise or lower the mechanism-case and carbons by turning the nut 10 by the hand, it being peripherally milled for this purpose. I now make the nut to with bevel gear-teeth and arrange a bevel-pinion a to mesh with it, this pinion being fixed on a short shaft T, on which shaft is awheel or knob O, by turning which the nut to is rotated and the mechanism-case and carbons are propelled up or down. The shaft T is borne by a bracketarm U, which extends upward from a split sleeve U, which embraces the tube t and can be turned around the latter to cause the shaft T to radiate from the center in any di rection desired, whereupon the sleeve is fastened by tightening its clamping-screw. The carbons may be adjusted vertically by reaching the hand inside the projector-casing and turning the wheel 0; but when the lamp is inclosed within a casing it is preferable to employ the construction shown in Figs. 1 and 2, where a supplemental shaft T is coupled to the shaft T by means of a universal joint w and extends out through the projectorcasing and has a hand-wheel 0 on its outer end. The universal joint enables the position of the lamp to be freely adjusted in horizontal direction by means of the set-screw S and plates F and G without interfering with the action of the mechanism for adjusting the carbons vertically. The supplemental shaft T and universal joint are also desirable in the case of a locomotive head-light, so that the wheel 0 may be carried back into the cab, the shaft T being in one or more sections coupled together by universal joints and mounted in any suitable guides or bearings, whereby obstructions on the locomotive may be avoided. It is important that the vertical adjustment of the carbons shall be within immediate control of the engineer, since the position of the arc may be accidentally changed at any instant by the breaking off of one or other of the carbons, which necessitates an adjustment of thecarbon-holders up or down in order to restore the arc to coincidence with the focus of the reflector.

In the front of the case C is set a pointed pin .2, (shown in Figs. 1 and 2,) which serves as a gage for indicating the proper position of the focus or are, and aids in the setting of the lamp and the adjustment of the carbons.

It will be understood that my invent-ion in its broader features is not limited to the construction of the carbon-holders to slide upon fixed vertical guides or guide-rods, or upon the particular construction or arrangement of these guides.

Although I have referred to the are as being located in front of and on a level with the mechanism-case, it will be understood that it may be somewhat above or below the level of the case, and that the axis of the carbons instead of being in front may be arranged on any side of the case, it being only essential that it be exterior thereto and that the carbons be held from above and below the case, or, in other words, that when the carbon-holders are spread apart to the utmost extent, the one shall be above the case and the other shall be below it.

It is also to be understood that the feeding mechanism may be operated by eleetro-magnets or solenoids and by one or more magnets or solenoids, according to any arrangement that is known in the art as being a substantial equivalent of that shown.

I claim as my invention the following defined novel features and combinations, substantially as hereinbefore specified, viz:

1. In a focusing electric lamp, the combination of a mechanism-case, regulating mechanism inclosed therein, vertical guides borne by the case fastened to the exterior thereof and extending above and below the case, the positive and negative carbon holders constructed to slide on said guides, racks exterior to the case attached to the respective carbon-holders and extending vertically past each other, pinions engaging said racks, and a feedingshaft on which said pinions are fixed, extending into the case and forming part of the regulating mechanism.

2. In a focusing electric lamp, the combination of a mechanism-case, regulating mechanism inelosed therein, vertieal guides borne by the ease fastened. to the exterior thereof and extending continuously from top to bottom above and below the case, positive and negative carbon holders constructed with slides engaging and sliding on said guides, the one engaging the upper part of the guides and the other the lower part ot' the same guides, and each slide movable from its end. portion of the guides toward the other slide and to the middle portion of: the guides, racks exterior to the cas(. attaehed to therespective carbon holders and. extending VOlll-lcitll) past each other, pinions engaging said racks, and a feeding-shaft on which said pinions are lixed, extending into the case and forming part of the regulating mechanism.

3. The combination, with. the mechanismease, fixed vertical guides, and carbon-holders constructed to slide on said guides and having brackets projecting outwardly and. ez'trrying the earl)on-elamps, of a counterweight for the carbon-holdcn mounted on an arm on the side ot' the slide opposite to the bracket and clamp.

l. The combination, with the meclntnismcase of exterior vertical. guides consist ing of rods ll. ll, fastened. at their middle portion to the ease, and fastened together byerossheads at their top and bottom ends, and the positive andv negative carbon holders 1 and. 1), formed with slides .I and J, respectively, each ot said slides engaging both rods ll l], the slide J, movable over the portion of the rods above the fastening to the ease, and the slide J, movable over the portion of the rods below such fastening, racks c, fastened at their ends to the respective holders and extending vertically past each other parallel with theguide-rods, and a feeding-shaft K, near the middle fastening oil the 'uide-rods, having piuionsff meshing with said racks.

In a focusing electric lamp, the combination, with the meehanism-ease, and the positive and negative carbon holders and their racks arranged exterior to said ease,ot exterior pins engaging said racks, a feeding-shalt on which said pinions are lixed,whieh extends thence within. the ease and which is mounted. in stationary bearings, a ilfeedingtrain having a terminal. detent-wheel. and arranged. with its leading pinion meshing with a gear on said shaft and movable bodily up and down, and an eleetro-magnct having its movable member connected to said train and adapted. to impart up or down movement thereto, whereby during said up or down movement the leading pinion ot' the train meshes tangentially with said gear-wheel and turns the latter after the manner of a rack.

(3. The combination, with the meelntnismcase and carbon-holders in an axis outside thereof, of a supporting standard beneath said ease terminating .in a bottom plate, and astationary base-plate beneath said. bottom plate, withv a concentric swiveled connection between said st'aiulard and base-plate, whereby the mechanism-case can be partially rotated axially to move the carbons laterally, in order to rez'tdjust their total position, and a clamping-screw t'or tightening said stand ard after adjustment.

7. The combination, with a focusing electric lamp lmving the axis ol' its carbon-holders outside elf the meehanism-easo, ot' a vertical. standard on which its mechanism-ease is mounted, said. staiulard terminating in aboltom late, a statiomn'y base-plate on which said bottom plate rests, and a combinedswiveled and sliding connection between the standard and base-plate, consisting ot' a slot through the bottom plate extending in a direction toward and from the axis ot the earlJOll-llOltlQlS, and a clamping screw passing through said slotand cligagiilgthebase-plato, whereby the standard may be slid btalily to move the carbons itorward. or back, or osci| lated to displace them laterally, the local adjustmentol the axis of thecarbons boingthus adjustable by the manipulation of a single screw.

8. The combiinltion, with. a it'otieusing chic trio lamp and its base-plate, ol. a horizontally adj ustable connection between. thtan,whtn'cliv the axis of the carbons maybe shittethavertical adjustment for the lamp, whereby the are may be raised or lowered, a laterally-projecting shat't geared to the vertical :uljusting devices for iniparting motion thereto, and a supplemental. shaft connected. to said shaft through the medium off a nnivm'sal joint, whereby the mechanism for el'tecting the vertical adjustment is not in lluenced by the horizontal tltljl'lflllllOllii ol' the lamp.

9. The combination, with. a focusing electric lamp, of a telescopically-extensible vertical standard on. which it is nu'nlnted, a nut turning on one section ot said Sl'itlltlli'tl and engaging a sr.:rewthread on the other for ex tending the stamlard and t'ormedv with bevel gem-teeth, and. a laterallyn-ojceting shat't having a bevel-pinion engaging the teeth on said. nut t'or eomnuinieating rotary movement thereto, with a bearing-arm. .t'or sulmorting said. shaft, and a clamping-sleeve embracing the fixedv member of the lILlUStODlC standard, and adjustable around. the latter in order to bring the lateral]y-jn'ojeeti ng shaft to any position around the vertical axis.

10. In a focusing electric lamp, the combination, with the mechanism-r: s oi? a telescopically extensible vertical standard on which it is mounted, eonstrluicted with a stationary section, a vertically-nu vable section tixed to the meehanism-case, and a nut turning on one of said sections and. engaging: serew-thread on the othtn', exterior guides for preventing the turning of the mechanismcase, constructed with one member tixed. to the stationary section of the stamlard. and the other member connected to the nu-char ism-ease, and with stops in connection with saidv exterior guides .t'or limiting the vertical adjustment of the mechanisntease.

11. In a focusing electric lamp, the combination, with the mechanism-case, the carbon-holders, and vertical guides therefor arranged exterior to the case and fastened thereto, of a telescopically extensible standard on which the case is mounted, and guides for preventing the turning of the mechanismcase, constructed with one member fixed to the stationary section of the standard and the other member fixed to the lower portion of the carbon-holder guides.

12. In a focusing electric lamp, the combination, with the mechanism-case O, the carbon-holders, and vertical guides H H therefor fixed to the exterior of the case, of the my name in the presence of two subscribing witnesses.

JAMES J. \VOOD. Vitnesses:

ARTHUR C. FRASER, J NO. E. GAVIN. 

